A method is known for acid-salt treatment of near-mine zone of layers comprising carbonate rocks (see Suchkov B. M. Intensifying Oil Wells Output-Moscow-Izhevsk: Scientific Research Center “Regular and chaotic dynamics,” Computer Research Institute, 2007, pp. 145-150), according to which an operational acid-salt solution is pumped into the extraction and injection wells drilled at the deposits. The operational acid-salt solution is a 12-15% or 24-28% solution of acid-salt with additions of surface-active agents, corrosion inhibitors, and acetic acid. The acid-salt solution is kept within the treated layers for some time, wherein the treatment regime is selected according to the following principle; if the permeability of the layer is low, the pressure of solution is increased, and if the depth of the layer is greater, the solution is pumped at a higher speed.
The main disadvantages of the method are:                the acid solution may be substantially diluted with the layer waters that are almost always present in oil and gas layers;        once the acid concentration of the operational solution is decreased to a certain level, the secondary residue formation process may start within layers, resulting in formation of non-soluble salts, which block the cracks and pores in layers;        the method results in uneven activity of the acid solutions on cracks, especially given differences between permeabilities of certain layers and interlayers and presence of large cracks and layer rock continuity breaks. In such circumstances, all of the operational solution goes to the most open interlayer or into the cracks within the continuity break zones, since it is not possible to alter the operational solution viscosity;        or, in contrast, the method can lead to the above-normal influence of acid solutions of the formations, which results in closing of the cracks, thus reducing filtering of the layers;        efficiency of recurring treatments decreases and deep layer treatments cannot be carried out multiple times;        due to high corrosion activity of the operational solution, well equipment and pipes quickly collapse after layer treatment.        
A method is also known for oil-acid treatment of near-mine zone of layers. (See Suchkov B. M. Intensifying Oil Wells Output-Moscow-Izhevsk: Scientific Research Center “Regular and chaotic dynamics,” Computer Research Institute, 2007, p. 441). In this known method, an operational liquid is a mixture of oil, which acts as a solvent for resin-paraffin sediments, and an acid, which acts as a solvent for salts of carbonate and terrigenous sediments. The operational liquid is formed as an emulsion by adding emulsifier ES-2. This method is efficient only for highly porous layers with visibly expressed discontinuity of layer thickness.
The disadvantages of this method for treatment of near-mine zones of layers include a limited area of use of the method and a very low efficiency in low permeability layers due to high viscosity of operational liquid (emulsion), because its viscosity cannot be altered. Yet another serious disadvantage is the high cost of the emulsifier ES-2 needed to prepare the operational mixture.
Yet another method is known for treating near-mine zones, comprising sediments of hydrocarbon compounds, which is based on use of chemical agents that possess high dissolvability and inhibiting activity on organic sediments with a complex composition having above-normal concentration of asphaltens and resins. (See Suchkov B. M. Intensifying Oil Wells Output-Moscow-Izhevsk: Scientific Research Center “Regular and chaotic dynamics,” Computer Research Institute, 2007, pp. 473-474). According to this known method, operation fluids are pumped into extraction and injection wells drilled at the formation to treat near-mine zones and to displace oil from the layers, the wells are repaired and the pipes and the equipment therein are subjected to anti-corrosion treatment, and in low surface temperature conditions, the pipes in upper portions of the sediments are cleaned from asphalt-resin-paraffin sediments. The sediment cleaning agents are based on alkyl-substituted benzene hydrocarbons, such as butylbenzene, benzyl toluene and others, that represent the bulk byproduct of oil production industry. During treatment of deep wells, the mixtures are used that further include, besides the substances specified above, saturated hydrocarbons, for example, stable natural gasoline with 0.1-1.5% w.t. additions of oil-soluble SAA (surface-active agents), i.e. aliphatic amines or compositions of the subset of non-saturated aliphatic acids, such as agent “IKNS AzNIPIneft 72.” Concentration of benzene hydrocarbons in mixtures is determined based on a composition of hydrocarbon sediments in near-mine zone of formations and is increased with the content of high molecular asphaltens and resins in the sediments. Solvents of SAA added into mixtures decrease surface tension, disperse asphaltens and resins and facilitate the dissolution process. The compositions used in this method facilitate a better cleaning of near-mine zones of layers from heavy hydrocarbon compositions and slow down subsequent sediment formation. Water solutions of sodium oxide silicates and hydrates with concentration not exceeding 38-45% are used as inhibitor agents. Their effect is based on the adsorption processes in the interphase boundary. Asphaltens and resins disperse by means of inhibiting effect with use of sodium oxide silicates and hydrates.
The method has the following disadvantages:                it is impossible to change viscosity and density of solvent mixtures, which substantially decreases scope of their use—they can only be used under limited conditions with high temperatures in the bottoms of the wells, which are necessary for intensive dissolution of sediments and are only present at great depths in drilled weds;        it is impossible to use these solvent mixtures in developed systems of large cracks and layer continuity breaks, as well as after hydraulic fracturing of rock layers, wherein in about 90% of extraction wells, in order to increase rate of inflow of oil and gas, large horizontal and vertical cracks are formed in layers. In such systems, the mixtures will fully filtrate into these large cracks, as well as penetrate into inter layers with good permeability, causing the layers with lower permeability to remain untreated, which will significantly decrease efficiency of treatment of near-mine zones of layers throughout extraction wells and efficiency of injection wells killing due to remaining large area and zones in layers that have not been subjected to oil displacement;        the solvent mixture are very high in cost.        